Electronic devices having multiple alignment layers

ABSTRACT

A method for forming an electronic device including two stacked liquid crystal cells is disclosed. A first liquid crystal cell including two substrates is provided. A second liquid crystal cell is formed by disposing another substrate to one of the substrates of the first liquid crystal cell. Subsequently, a cutting step is performed to cut off unnecessary portions of the substrates of the first liquid crystal cell and the second liquid crystal cell. Before bonding the another substrate, a pre-cutting step is performed to form at least a pre-cutting mark on the substrate on which the another substrate is bonded in order to facilitate removal of unnecessary portions of the substrates.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. application Ser.No. 15/931,594, filed on May 14, 2020, which claims the benefit of U.S.Provisional Application No. 62/849,168, filed on May 17, 2019. Thecontents of these applications are incorporated herein by reference.

BACKGROUND OF THE DISCLOSURE 1. Field of the Disclosure

The present disclosure relates to an electronic device, and moreparticularly, to an electrically controlled light-adjusting device.

2. Description of the Prior Art

A light-adjusting device (also known as an electrically controlledlight-adjusting device, an electrically controlled device or anintelligent light-adjusting device) is a kind of electrochromic devicewhich may adjust the color or intensity of light by applying a controlvoltage to a functional material layer of the device.

Currently, extensive research has been conducted on the development ofelectrically controlled light-adjusting devices. However, there arestill many technical issues to be overcome. For example, how to furtherreduce the light transmittance of the light-adjusting device in a lowtransmission state to increase shielding efficiency and enlargeadjustable range between a high transmission state and a lowtransmission state are still under aggressive research in the technicalfield.

SUMMARY OF THE DISCLOSURE

The present disclosure is directed to an electronic device and a methodfor forming the same.

One embodiment of the present disclosure provides a method for formingan electronic device. First, a first liquid crystal cell is provided.The first liquid crystal cell includes a first substrate and a thirdsubstrate. Subsequently, a pre-cutting step is performed to form atleast a pre-cutting mark on the third substrate. Following, a secondliquid crystal cell is formed by disposing a second substrate with asecond conductive layer to the third substrate. After that, a cuttingstep is performed to cut off portions of the first substrate and thesecond substrate and concurrently removing a portion of the thirdsubstrate along the pre-cutting mark.

One embodiment of the present disclosure provides electronic deviceincluding a first substrate, a second substrate on the first substrate,a third substrate between the first substrate and the second substrate,a first optical media layer between the first substrate and the thirdsubstrate, and a second optical media layer between the second substrateand the third substrate. A sidewall of the third substrate is recessedfrom a sidewall of the first substrate and a sidewall of the secondsubstrate to form a recessed portion, and another sidewall of the thirdsubstrate protrudes from another sidewall of the first substrate andanother sidewall of the second substrate to form a protruding portion.

One embodiment of the present disclosure provides electronic deviceincluding a first substrate, a second substrate on the first substrate,a third substrate between the first substrate and the second substrate,a first optical media layer between the first substrate and the thirdsubstrate, and a second optical media layer between the second substrateand the third substrate, wherein the first substrate, the thirdsubstrate and the second substrate are displaced layer by layer along adirection parallel to a surface of the first substrate to form a steppedstructure.

The electronic device provided by the present disclosure may have areduced overall thickness and manufacturing cost by sharing the thirdsubstrate between the first liquid crystal cell and the second liquidcrystal cell. Furthermore, by performing the pre-cutting step, it wouldbe easier to remove the unnecessary portions of the substrates of thefirst liquid crystal cell and the second liquid crystal cell during thecutting step. The recessed portion, protruding portion, and/or steppedstructure of the electronic device may facilitate electrical connectingto the conductive layers of the first liquid crystal cell and the secondliquid crystal cell.

These and other objectives of the present disclosure will no doubtbecome obvious to those of ordinary skill in the art after reading thefollowing detailed description of the embodiment that is illustrated inthe various figures and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 , FIG. 2 , FIG. 3 and FIG. 4 are schematic diagrams illustratingthe cross-sectional structures of an electronic device at differentmanufacturing steps according to a first embodiment of the presentdisclosure.

FIG. 5 is a schematic diagram illustrating the cross-sectional structureof an electronic device according to a second embodiment of the presentdisclosure.

FIG. 6 is a schematic diagram illustrating the cross-sectional structureof an electronic device according to a third embodiment of the presentdisclosure.

FIG. 7A, FIG. 7B, FIG. 8A and FIG. 8B are schematic diagramsillustrating the orientations of the liquid crystal molecules and thedye molecules of the dye-doped liquid crystal layer according to someembodiments, in which:

FIG. 7A is a schematic diagram illustrating the orientations of thepositive liquid crystal molecules and the positive dye molecules of thedye-doped liquid crystal layer when no electrical field is applied;

FIG. 7B is a schematic diagram illustrating the orientations of thepositive liquid crystal molecules and the positive dye molecules of thedye-doped liquid crystal layer when an electrical field is applied.

FIG. 8A is a schematic diagram illustrating the orientations of thenegative liquid crystal molecules and the negative dye molecules of thedye-doped liquid crystal layer when no electrical field is applied.

FIG. 8B is a schematic diagram illustrating the orientations of thenegative liquid crystal molecules and the negative dye molecules of thedye-doped liquid crystal layer when an electrical field is applied.

FIG. 9 is a schematic diagram illustrating a path of light passingthrough an electronic device according to an embodiment of the presentdisclosure.

DETAILED DESCRIPTION

The present disclosure may be understood by reference to the followingdetailed description, taken in conjunction with the drawings asdescribed below. It is noted that, for purposes of illustrative clarityand being easily understood by the readers, various drawings of thisdisclosure show a portion of the electronic device, and certaincomponents in various drawings may not be drawn to scale. In addition,the number and dimension of each component shown in drawings are onlyillustrative and are not intended to limit the scope of the presentdisclosure.

Certain terms are used throughout the description and following claimsto refer to particular components. As one skilled in the art willunderstand, electronic equipment manufacturers may refer to a componentby different names. This document does not intend to distinguish betweencomponents that differ in name but not function. In the followingdescription and in the claims, the terms “include”, “comprise” and“have” are used in an open-ended fashion, and thus should be interpretedto mean “include, but not limited to . . . ”. It will be understood thatwhen a component is referred to as being “connected to” anothercomponent (or its variant), it can be directly connected to the “anothercomponent”, or connected to the another component through one or moreintervening components.

It will be understood that when an element or layer is referred to asbeing “on” or “connected to” another element or layer, it can bedirectly on or directly connected to the other element or layer, orintervening elements or layers may be presented. In contrast, when anelement is referred to as being “directly on” or “directly connected to”another element or layer, there are no intervening elements or layerspresented.

Although the terms such as first, second, etc. may be used in thedescription and following claims to describe various components inclaims, these terms doesn't mean or represent the claimed componentshave order and doesn't represent the order of one claimed component andanother one claimed component, or the sequence in manufacturing method.These terms are used to discriminate a claimed component with adenomination from another one claimed component with the samedenomination.

It should be noted that the technical features in different embodimentsdescribed in the following description can be replaced, recombined, ormixed with one another to constitute another embodiment withoutdeparting from the spirit of the present disclosure.

The term “transmittance (T)” described in this disclosure indicates theability of light to pass through the medium and is generally expressedas the percentage of the luminous flux passing through the medium to theincident luminous flux, such as 0% to 100%. A transmittance of 0%indicates the light being completely absorbed by the medium. Atransmittance of 100% indicates the light completely passes through themedium. The terms “high transmission state” and “low transmission state”of a medium described in this disclosure are relative terms that “hightransmission state” has transmittance higher than the transmittance ofthe “low transmission state”. According to some embodiments, the “hightransmission state” is the state of the electronic device at the highesttransmittance that can be achieved. For example, the transmittance ofthe electronic device in the high transmission state may be greater thanor equal to 30% and less than or equal to 100%, or between any rangesdefined by the above values. On the other hand, the “low transmissionstate” is the state of the electronic device at the lowest transmittancethat can be achieved. For example, the transmittance of the electronicdevice in the low transmission state may be less than or equal to 20%and greater than or equal to 0%, or between the range defined by theabove values. The ratio of the transmittance of “high transmittance” tothe transmittance of “low transmittance” is the contrast of theelectronic device.

The electronic device provided in the embodiments of the presentdisclosure may be an electrically controlled device, which may beapplied in the fields of architecture, automobiles, interior decoration,signboards, window or optical devices, but not limited thereto.

FIG. 1 , FIG. 2 , FIG. 3 and FIG. 4 are schematic diagrams illustratingthe cross-sectional structures of an electronic device at differentmanufacturing steps according to a first embodiment of the presentdisclosure. Please refer to FIG. 3 . The electronic device 1 includes afirst liquid crystal cell 1A and a second first liquid crystal cell 1B.The first liquid crystal cell 1A includes a first substrate 10 and athird substrate 30 opposite to each other. Between the first substrate10 and the third substrate 30 are a first conductive layer 12 and afirst alignment layer 14 disposed on a surface 10 a of the firstsubstrate 10 and a third conductive layer 32 and a third alignment layer34 disposed on a surface (such as a first surface 30 a) of the thirdsubstrate 30. The surface 30 a of the third substrate 30 is closer tothe first substrate 10. The first conductive layer 12 is disposedbetween the first substrate 10 and the first alignment layer 14. Thethird conductive layer 32 is disposed between the third substrate 30 andthe third alignment layer 34. Furthermore, a sealant 40 is disposedbetween the first substrate 10 and the third substrate 30 and at twosides of the first alignment layer 14 and the third alignment layer 34for sealing a space that is filled by an optical media layer. In theembodiment, the space sealed by the sealant 40 may be filled with afirst dye-doped liquid crystal layer 50, but not limited thereto. Thefirst dye-doped liquid crystal layer 50 is disposed between the firstalignment layer 14 and the third alignment layer 34. In someembodiments, optionally, a dummy sealant 42 may be disposed between thefirst substrate 10 and the third substrate 30 and positioned outside thesealant 40. The second liquid crystal cell 1B includes a secondsubstrate 20 and the third substrate 30 opposite to each other. Betweenthe second substrate 20 and the third substrate 30 are a secondconductive layer 22 and a second alignment layer 24 disposed on asurface 20 a of the second substrate 20 and a fourth conductive layer 36and a fourth alignment layer 38 disposed on a surface (such as thesecond surface 30 b) of the third substrate 30 that is opposite to thefirst surface 30 a. The surface 30 b of the third substrate 30 is closerto the second substrate 20. The second conductive layer 22 is disposedbetween the second substrate 20 and the second alignment layer 24. Thefourth conductive layer 36 is disposed between the third substrate 30and the fourth alignment layer 38. Furthermore, a sealant 44 is disposedbetween the second substrate 20 and the third substrate 30 and at twosides of the second alignment layer 24 and the fourth alignment layer 38for sealing a space that is filled by an optical media layer. In theembodiment, the space sealed by the sealant 44 may be filled with asecond dye-doped liquid crystal layer 52, but not limited thereto. Thesecond dye-doped liquid crystal layer 52 is disposed between the secondalignment layer 24 and the fourth alignment layer 38. In someembodiments, optionally, a dummy sealant 46 may be disposed between thesecond substrate 20 and the third substrate 30 and positioned outsidethe sealant 44. In some embodiments, a spacer (photospacer, not shown)may be included between the first substrate 10 and the third substrate30 and/or between the second substrate 20 and the third substrate 30. Insome embodiments, an insulating layer, an optical film, ananti-reflection layer, or the like may be provided on the surface 10 bof the first substrate 10 and the surface 20 b of the second substrate20, but not limited thereto. In some embodiments, the optical films mayinclude anti-ultraviolet light films, optical filters or other suitableoptical films, but not limited thereto.

According to some embodiments, the first liquid crystal cell 1A and thesecond liquid crystal cell 1B may be manufactured by the followingprocess. First, as shown in FIG. 1 , the first substrate 10 is provided.Subsequently, the first conductive layer 12 is formed on the surface 10a of the first substrate 10 by, for example, deposition, plating, orcoating. Later, the first alignment layer 14 is formed on the firstconductive layer 12. After forming the sealant 40 and the dummy sealant42, a one drop fill (DOF) process may be performed to drop the liquidcrystal molecules with doped dye molecules in the region surrounded bythe sealant 40 thereby forming the first dye-doped liquid crystal layer50. Afterword, the third substrate 30 having the third conductive layer32 and the third alignment layer 34 disposed thereon is bonded to thefirst substrate 10. In other embodiments, the first liquid crystal cell1A may be manufactured by bonding the first substrate 10 and the thirdsubstrate 30 to make the space for accommodating the liquid crystalmolecules and then injecting the liquid crystal molecules with doped dyemolecules into the space by performing a vacuum suction process. Theabove manufacturing process should be known in the art and the detailedmanufacturing steps are not narrated herein for the sake of simplicity.As shown in FIG. 1 , before the third substrate 30 is bonded to thefirst substrate 10, the fourth conductive layer 36 may be formed inadvance on the second surface 30 b that is opposite to the first surface30 a of the third substrate 30 in order to simplify the process. Itshould be understood that in other embodiments, the fourth conductivelayer 36 may be formed on the second surface 30 b of the third substrate30 after bonding the first substrate 10 and the third substrate 30.

The first substrate 10 and the third substrate 30 may be hard substratesor flexible substrates. The materials of the first substrate 10 and thethird substrate 30 may include glass, quartz, sapphire, plastic, othersuitable materials, or a combination thereof. The plastic materials ofthe first substrate 10 and the third substrate 30 may include, forexample, polyimide (PI), polycarbonate (PC), polyethylene terephthalate(PET), other suitable plastic materials, or a combination thereof, butnot limited thereto. According to an embodiment of the presentdisclosure, the first substrate 10 and the third substrate 30 may besoda-lime glass substrates, but are not limited thereto.

The first conductive layer 12 and the third conductive layer 32 mayinclude transparent conductive materials, such as indium tin oxide(ITO), antimony doped tin oxide (ATO), and fluorine doped tin oxide(FTO), but not limited thereto.

The first alignment layer 14 and the third alignment layer 34 have theability to align liquid crystal molecules, so that the liquid crystalmolecules are aligned in a specific alignment direction. The firstalignment layer 14 and the third alignment layer 34 may be manufacturedby, for example, coating an alignment material (such as polyimide, PI)on the substrate and then performing an alignment treatment to thealignment material, such as rubbing alignment treatment, photo alignmenttreatment, ion beam alignment treatment, plasma beam alignment, but notlimited thereto. According to an embodiment of the present disclosure,the alignment directions of the first alignment layer 14 and the thirdalignment layer 34 are substantially perpendicular to each other.

The first dye-doped liquid crystal layer 50 includes liquid crystalmolecules and at least one type of dye molecules. Due to the refractiveindex anisotropy of liquid crystal molecules, light with differentpolarization directions will have different refractive indices whenpassing through liquid crystal molecules. Accordingly, liquid crystalmaterials may modulate the polarization direction of light. Each of theliquid crystal molecules may a shape equivalent to long strip (longrod). The direction of a long axis (molecular axis) of each of theliquid crystal molecules is consistent with the direction of an opticaxis of the liquid crystal molecule. In addition, according to thedielectric anisotropy of the liquid crystal molecules, the liquidcrystal molecules may be positive-type (positive dielectric anisotropy)or negative-type (negative dielectric anisotropy). More specifically,when the long axis of the liquid crystal molecule is parallel to thedirection of the applied electric field, the liquid crystal molecules ispositive-type. On the other hands, when the short axis of the liquidcrystal molecule is parallel to the direction of the applied electricfield, the liquid crystal molecule is negative-type. According to anembodiment of the present disclosure, the first dye-doped liquid crystallayer 50 may include nematic liquid crystal molecules, smectic liquidcrystal molecules, or cholesterol liquid crystal molecules, but are notlimited thereto. The first dye-doped liquid crystal layer 50 may furtherinclude other components, such as chirality molecules or otherproperty-adjusting components.

The dye molecules in the first dye-doped liquid crystal layer 50 may beany suitable dichroic dyes. For example, the dye molecules suitable forthe first dye-doped liquid crystal layer 50 may have a geometricanisotropy, long-rod shaped with a long axis (molecular axis) and ashort axis, and different absorption rates for visible light along thelong axis and the short axis. In particular, selective absorption ofdichroic dyes is more obvious for polarized lights. Dye moleculesabsorbing light component parallel to the long axis (light absorptionaxis) are positive-type dichroic dye. In contrast, dye moleculesabsorbing light component parallel to the short axis are negative-typedichroic dye.

It is noticeable that the orientations of the dye molecules and theliquid crystal molecules in the dye-doped liquid crystal layer 50 aresignificantly correlated and the long axes of the dye molecules areusually parallel to the long axes of the liquid crystal molecules. Thisis because that the dye molecules may be forced to twist by the liquidcrystal molecules. For example, as shown in FIG. 7A, the molecular axis50′ of the liquid crystal molecules are naturally parallel to the firstalignment direction 14 a of the first alignment layer 14, and themolecular axis 50 b′ of the dye molecules are parallel to the molecularaxis 50′ of the liquid crystal molecules and the first alignmentdirection 14 a of the first alignment layer 14. For example, in anembodiment, the first alignment direction 14 a may be the direction D2,and consequently the molecular axis 50′ of the liquid crystal moleculesand the molecular axis 50 b′ of the dye molecules are parallel to thedirection D2. Therefore, by controlling the orientations of the liquidcrystal molecules by applying an electric field, the control over theorientations and the light-absorbing states of the dye molecules may beachieved.

The type of dye molecules may be selected based on filling ability andcompatibility with the liquid crystal molecules. Other factors such aslight resistance (light stability) and heat resistance (thermalstability) are also important. According to an embodiment of the presentdisclosure, the dye molecules of the dye-doped liquid crystal layer 50may absorb visible light. For example, the dye molecules may absorblight of wavelength between 380 nm and 780 nm. According to anembodiment of the present disclosure, the dye molecules, for example,may be azo-based dichroic dyes or anthraquinone-based dichroic dyes.

Please refer to FIG. 2 . The second liquid crystal cell 1B may bemanufactured on the first liquid crystal cell 1A. For example, thefourth alignment layer 38 is then formed on the fourth conductive layer36 on the second surface 30 b of the third substrate 30. Afterward, apre-cutting step is performed on the third substrate 30 to form apre-cutting mark 60 on the third substrate 30 to define a portion of thethird substrate 30 (and the conductive layers thereon) to be removed ina later process. The pre-cutting mark 60 may be approximately locatedbetween the sealant 40 and the dummy sealant 42. The dummy sealant 42may provide temporary support for the pre-cut portion of the thirdsubstrate 30 and prevent it from peeling off in subsequent processes.The materials and manufacturing methods of the fourth conductive layer36 and the fourth alignment layer 38 may be the same with respect to thefirst conductive layer 12, the third conductive layer 32, the firstalignment layer 14 and the third alignment layer 34 as described above,and are not repeated here for the sake of simplicity.

Please refer to FIG. 3 . Subsequently, the sealant 44 and the dummysealant 46 disposed outside the sealant 44 are formed on the secondsurface 30 b of the third substrate 30. The second dye-doped liquidcrystal layer 52 is then formed in the area surrounded by the sealant44. Afterward, the second substrate 20 having the second conductivelayer 22 and a second alignment layer 24 formed on the surface thereforeis provided and bonded to the third substrate 30 by the sealant 44 andthe dummy sealant 46. As shown in FIG. 3 , the second conductive layer22 and the second alignment layer 24 are disposed on the surface 20 a ofthe second substrate 20 and face the third substrate 30. According to anembodiment, the second dye-doped liquid crystal layer 52 may be formedby one drop fill (DOF) process before bonding the second substrate 20 tothe third substrate 30, or by vacuum suction process after bonding thesecond substrate 20 to the third substrate 30, but not limited thereto.Subsequently, a cutting step is performed to cut the first substrate 10along the cutting mark 62 and cut the second substrate 20 along thecutting mark 64. Then, the unnecessary portions of the first substrate10, the second substrate 20 and the third substrate 30 and films thereonare removed along the cutting marks 62 and 64 and the pre-cutting mark60 to obtain the structure shown in FIG. 4 . It is noteworthy that thepre-cutting mark 60 is formed by partially cut the third substrate 30without cutting through the third substrate 30. The unnecessary portionsof the third substrate 30 are removed at the same time when cutting thefirst substrate 10 and the second substrate 20. The second dye-dopedliquid crystal layer 52 includes liquid crystal molecules and at leastone type of dye molecules. According to an embodiment of the presentdisclosure, the second dye-doped liquid crystal layer 52 may include thesame composition as the first dye-doped liquid crystal layer 50. Forexample, the second dye-doped liquid crystal layer 52 and the firstdye-doped liquid crystal layer 50 may have same liquid crystal moleculesand dye molecules, but the proportion of the compositions may beadjusted according to demand.

According to some embodiments of the present disclosure, the pre-cuttingand cutting steps may make the sidewalls of the first substrate 10, thethird substrate 30, and the second substrate 20 misaligned along thenormal direction of the surface 10 a of the first substrate 10 (such asthe direction D1). That is, the sidewalls of the first substrate 10, thethird substrate 30, and the second substrate 20 are not located on asame vertical plane. In this way, the required electrical connectionsbetween the first conductive layer 12, the third conductive layer 32,the fourth conductive layer 36, and the second conductive layer 22 maybe obtained. For example, as shown in FIG. 4 , a part of the sidewall ofthe third substrate 30 (the sidewall 30 c on the right side in FIG. 4 )is recessed from the sidewall 10 c of the first substrate 10 and thesidewall 20 c of the second substrate 20 to form a recessed portion 80of the electronic device 1. In other words, along the direction D1perpendicular to the surface 10 a of the first substrate 10, thesidewall 10 c of the first substrate 10 and the sidewall 20 c of thesecond substrate 20 protrude from the sidewall 30 c of the thirdsubstrate 30. The third substrate 30 does not overlap some portions ofthe first conductive layer 12 and the second conductive layer 22. Theportions of the first conductive layer 12 and the second conductivelayer 22 not overlapped by the third substrate 30 are exposed in therecessed portion 80 and may be used as contact points for providingelectrical connections, such as the electrode 12 a (the range designatedas 12 a in FIG. 4 ) for electrically contacting the first conductivelayer 12 and the electrode 22 a (the range designated as 22 a in FIG. 4) for electrically contacting the second conductive layer 22. Similarly,the sidewall 30 d (the sidewall 30 d on the left side in FIG. 4 ) of thethird substrate 30 protrudes from the sidewall 10 d of the firstsubstrate 10 and the sidewall 20 d of the second substrate 20 to form aprotruding portion 82 of the electronic device 1. Therefore, someportions of the third conductive layer 32 on the first surface 30 a ofthe third substrate 30 and the fourth conductive layer 36 on the secondsurface 30 b are exposed and may be used as contact points for providingelectrical connections, such as the electrode 32 a (the range designatedas 32 a in FIG. 4 ) for electrically contacting the third conductivelayer 32 and the electrode 36 a (the range designated as 36 a in FIG. 4) for electrically contacting the fourth conductive layer 36. In someembodiments, the width W1 of the first substrate 10 along a direction D2(such as the direction parallel to the surface 10 a of the firstsubstrate 10) may be different from the width W2 of the second substrate20 along the direction D2. In some embodiments, the width W1 of thefirst substrate 10 may be different from the width W3 of the thirdsubstrate 30 in the direction D2. For example, the width W1 may begreater than the width W2 and the width W3. The width relationshipbetween the first substrate 10, the second substrate 20 and the thirdsubstrate 30 is not limited to the above example. In some embodiments,the sidewall 10 d of the first substrate 10 and the sidewall 20 d of thesecond substrate 20 (on the left side in FIG. 4 ) may be aligned alongthe direction D1. The sidewall 10 c of the first substrate 10 and thesidewall 20 c of the second substrate 20 (on the right side in FIG. 4 )may be misaligned along the direction D1.

One advantage of the present disclosure is that the electronic device 1has the first liquid crystal cell 1A and the second liquid crystal cell1B being formed by using three substrates (the first substrate 10, thesecond substrate 20 and the third substrate 30 wherein the thirdsubstrate 30 is shared by the first liquid crystal cell 1A and thesecond liquid crystal cell 1B). In this way, the manufacturing time andcost may be reduced.

Please refer to FIG. 5 . FIG. 5 is a schematic structuralcross-sectional view of an electronic device according to a secondembodiment of the disclosure. The difference between the embodimentsshown in FIG. 4 and FIG. 5 is that, the electronic device in FIG. 5further has a first conductive adhesive 70 (such as conductive silverpaste) provided in the recess 80. The first conductive adhesive 70 maycover a part of the sidewall 30 c of the third substrate 30 and is indirect contact with the electrode 12 a of the first conductive layer 12and the electrode 22 a of the second conductive layer 22 to electricallyconnect the first conductive layer 12 and the second conductive layer22. Similarly, a second conductive paste 72 (such as conductive silverpaste) may be provided on the protruding portion 82 to cover a part ofthe sidewall 30 d of the third substrate 30, at least a part of theelectrodes 32 a of the third conductive layer 32 and at least a part ofthe electrodes 36 a of the fourth conductive layer 36 to electricallyconnect the third conductive layer 32 and the fourth conductive layer36.

Please refer to FIG. 6 . FIG. 6 is a schematic cross-sectional view ofthe electronic device according to a third embodiment of the presentdisclosure. The difference between the embodiments shown in FIG. 4 andFIG. 5 and FIG. 6 is that, sidewalls of the first substrate 10, thethird substrate 30, and the second substrate 20 of the electronic device1 shown in FIG. 6 are displaced layer by layer along the direction D2(such as the horizontal direction) parallel to the surface 10 a of thefirst substrate 10, thereby forming a stepped structure. In this way,the electrode 22 a of the second conductive layer 22 and the electrode32 a of the third conductive layer 32 may be exposed on one side of theelectronic device 1 (right side of FIG. 6 ) and the electrode 36 a ofthe fourth conductive layer 36 and the electrode 12 a of the firstconductive layer 12 may be exposed on the other side of the electronicdevice 1 (left side of FIG. 6 ) for further electrical connection. Itshould be understood that the structures shown in FIG. 4 and FIG. 6 aremerely examples, and are not intended to be a limitation to the ways ofpre-cutting and cutting steps of the present disclosure. The relativepositions of the first substrate 10, the second substrate 20 and thethird substrate 30 may be adjusted according to the needs of theapplication.

The parameters of the first liquid crystal cell 1A, the second liquidcrystal cell 1B, or a combination of the first liquid crystal cell 1Aand the second liquid crystal cell 1B may be measured using any suitablemeasuring devices. The parameters may include cell gaps, twist angles,pre-title angles, rubbing directions, retardations of lights passingthrough the first liquid crystal cell 1A and/or the second liquidcrystal cell 1B, polarizer efficiency, transmittances, absorption,depolarization, dichorism, but not limited thereto. According to anembodiment of the present disclosure, the first alignment direction 14 a(shown in FIG. 9 ) of the first alignment layer 14 and the thirdalignment direction 34 a (shown in FIG. 9 ) of the third alignment layer34 are substantially perpendicular to each other. For example, the firstalignment direction 14 a of the first alignment layer 14 and the thirdalignment direction 34 a of the third alignment layer 34 may have anincluded angle of 90±10 degrees, or between 80 and 100 degrees.According to an embodiment of the present disclosure, the thickness ofthe first liquid crystal cell 1A and the thickness of the second liquidcrystal cell 1B may be respectively between approximately 0.003millimeters (mm) and 0.03 millimeters, but not limited thereto. Thethicknesses of the electronic device comprising the first liquid crystalcell 1A and the second liquid crystal cell 1B may be betweenapproximately 1 mm and 20 mm, but not limited thereto. By adjusting thethickness of the liquid crystal cells, the optical modulation effect maybe increased.

According to the disclosure, the types of liquid crystal molecules anddye molecules may be selected based on application needs. The liquidcrystal molecules and dye molecules have good filling ability andcompatibility, and also have expected light resistance (light stability)and heat resistance (thermal stability). FIG. 7A, FIG. 7B, FIG. 8A andFIG. 8B are schematic diagrams illustrating the orientations of theliquid crystal molecules 50 a and dye molecules 50 b of the firstdye-doped liquid crystal layer 50 of the first liquid crystal cell 1A(or the second dye-doped liquid crystal layer 52 of the second liquidcrystal cell 1B) with and without an electric field being applied. Theliquid crystal molecules 50 a and dye molecules 50 b shown in FIG. 7Aand FIG. 7B are positive types. The liquid crystal molecules 50 a anddye molecules 50 b shown in FIG. 8A and FIG. 8B are negative types. Inorder to facilitate understanding of the disclosure, the molecular axis50 a′ (optical axis) of the liquid crystal molecules 50 a and themolecular axis 50 b′ (light absorption axis) of the dye molecules 50 bare also indicated in FIG. 7A, FIG. 7B, FIG. 8A and FIG. 8B.

Please refer to FIG. 7A. When no electric field is applied, themolecular axis 50 a′ of the positive liquid crystal molecules 50 a isnaturally parallel to the first alignment direction 14 a of the firstalignment layer 14. The liquid crystal molecules 50 a may graduallytwist layer by layer between the first alignment layer 14 and the thirdalignment layer 34. For example, the molecular axis 50 a′ of the layermost adjacent to the first alignment layer 14 is at an angle of 90±10degrees to the layer most adjacent to the third alignment layer 34. Thedye molecules 50 b may be forced to twist by the liquid crystalmolecules. When the light 100 passes through the dye-doped liquidcrystal layer 50 along the direction D1, light component parallel to themolecular axis 50 b′ of the dye molecules 50 b would be absorbed by thedye molecules 50 b layer by layer. As a result, the transmittance oflight 100 through the first dye-doped liquid crystal layer 50 may bereduced, and the electronic device is in a low transmission state (darkstate). Please refer to FIG. 7B. When an electric field having adirection D1 is applied between the first conductive layer 12 and thethird conductive layer 32, the positive liquid crystal molecules 50 amay respond to the electric field and twist at a specific angle wherethe molecular axis 50 a′ is parallel to the direction D1. The dyemolecules 50 b may twist with the liquid crystal molecules 50 a, havingthe molecular axis 50 b′ parallel to the direction D1. When the light100 passes through the dye-doped liquid crystal layer 50 along thedirection D1, due to the molecular axis 50 b′ of the dye molecules 50 bis substantially parallel to the electrical field and the molecular axis50 a′ of the liquid crystal molecules 50 a, most of the light 100 wouldnot be absorbed by the dye molecules 50 b. When the molecular axis 50 b′of the dye molecules 50 b is parallel to the electric field, the shortaxes of the dye molecules 50 b are perpendicular to the electric field.In some cases, only a small part of the light 100 may be absorbed by theshort-axis absorption of the dye molecules 50 b. As a result, theelectronic device is in a high transmission state (bright state). Bycontrolling the strength of the electric field, the inclination of theliquid crystal molecules 50 a may be adjusted, thereby controlling thelight transmittance of the electronic device between a high lighttransmission state and a low light transmission.

Please refer to FIG. 8A. When no electric field is applied, themolecular axis 50 a′ of the negative liquid crystal molecules 50 a isnaturally perpendicular to the first alignment direction 14 a of thefirst alignment layer 14. Accordingly, the molecular axis 50 b′ of thedye molecules 50 b is also perpendicular to the first alignmentdirection 14 a of the first alignment layer 14. Most of the light 100passes through the dye-doped liquid crystal layer 50 along the directionD1 would not be absorbed by the dye molecules 50 b, and the electronicdevice is in a high transmission state (bright state). Please refer toFIG. 8B. When an electric field having a direction D1 is applied betweenthe first conductive layer 12 and the third conductive layer 32, thenegative liquid crystal molecules 50 a may respond to the electric fieldand twist at a specific angle where the molecular axis 50 a′ is parallelto the first alignment direction 14 a of the first alignment layer 14and may gradually twist layer by layer between the first alignment layer14 and the third alignment layer 34. For example, the molecular axis 50a′ of the layer most adjacent to the first alignment layer 14 is at anangle of 90±10 degrees to the layer most adjacent to the third alignmentlayer 34. The dye molecules 50 b may be forced to twist by the liquidcrystal molecules. When the light 100 passes through the dye-dopedliquid crystal layer 50 along the direction D1, light component parallelto the molecular axis 50 b′ of the dye molecules 50 b would be absorbedby the dye molecules 50 b layer by layer. As a result, the transmittanceof light 100 through the first dye-doped liquid crystal layer 50 may bereduced, and the electronic device is in a low transmission state (darkstate).

It should be noted that the types and orientations of the liquid crystalmolecules shown in FIG. 7A, FIG. 7B, FIG. 8A and FIG. 8B are onlyexamples and are not intended to limit the scope of the presentdisclosure. In other embodiments not described herein, the liquidcrystal molecules (positive or negative) may be doped with negativedichroic dyes. Practically, the types and orientations of the liquidcrystal molecules and the doped dyes molecules may be adjusted accordingto the design of the conductive layers and application needs.

Please refer to FIG. 9 , which illustrates a path of light passingthrough an electronic device, such as the electronic device 1 shown inFIG. 4 according to an embodiment of the present disclosure. To simplifythe illustration, only shows the first alignment layer 14 disposed onthe first substrate 10 of the electronic device 1, the second alignmentlayer 24 disposed on the second substrate 20, and the third alignmentlayer 34 and the fourth alignment layer 38 disposed on the thirdsubstrate 30 are shown in FIG. 9 . For the ease of understanding, themolecular axis 50 a′ of the liquid crystal molecules 50 a (alsorepresenting the molecular axis 50 b′ of the dye molecules doped in thefirst dye-doped liquid crystal layer 50) of the first dye-doped liquidcrystal layer 50 located between the first alignment layer 14 and thethird alignment layer 34 is also shown. The molecular axis 52 a′ of theliquid crystal molecules 52 a (also representing the molecular axis 52b′ of the dye molecules doped in the second dye liquid crystal layer 52)of the second dye liquid crystal layer 52 between the fourth alignmentlayer 38 and the second alignment layer 24 is also shown. It should benoted that the orientations of the liquid crystal molecules shown inFIG. 9 are only examples. The types and orientations of the liquidcrystal molecules of the electronic device disclosed in this disclosureare not limited to that shown in FIG. 9 .

As shown in FIG. 9 , the first alignment direction 14 a of the firstalignment layer 14 and the third alignment direction 34 a of the thirdalignment layer 34 are perpendicular to each other and have an includedangle of 90±10 degrees. The fourth alignment direction 38 a of thefourth alignment layer 38 and the second alignment direction 24 a of thesecond alignment layer 24 are perpendicular to each other and have anincluded angle of 90±10 degrees. The first alignment direction 14 a andthe fourth alignment direction 38 a are parallel. The third alignmentdirection 34 a and the second alignment direction 24 a are parallel. Theliquid crystal molecules 50 a in the first dye-doped liquid crystallayer 50 may twist layer by layer between the first alignment layer 14and the third alignment layer 34. In some embodiments, the liquidcrystal molecules 50 a may twist layer by layer by 90±10 degree in totaland have the molecular axis 50 a′ from being parallel to the firstalignment direction 14 a to being parallel to the third alignmentdirection 34 a. The dye molecules 50 b also twist layer by layer withthe liquid crystal molecules 50 a and have the molecular axis 50 b′ frombeing parallel to the first alignment direction 14 a to being parallelto the third alignment direction 34 a. Similarly, the liquid crystalmolecules 52 a in the second dye-doped liquid crystal layer 52 may twistlayer by layer between the fourth alignment layer 38 and the secondalignment layer 24. Directions R1 shown in FIG. 9 represents thedirections of the molecular axis 50 a′ of the liquid crystal molecules50 a and the molecular axis 50 b′ of the dye molecules 50 b of differentlayers. Directions R2 shown in FIG. 9 represents the directions of themolecular axis 52 a′ of the liquid crystal molecules 52 a and themolecular axis 52 b′ of the dye molecules 52 b of different layers. Insome embodiments, the liquid crystal molecules 52 a may twist layer bylayer by 90±10 degree in total and have the molecular axis 52 a′ frombeing parallel to the fourth alignment direction 38 a to being parallelto the second alignment direction 24 a. The dye molecules 52 b alsotwist layer by layer with the liquid crystal molecules 52 a and have themolecular axis 52 b′ from being parallel to the fourth alignmentdirection 38 a to being parallel to the second alignment direction 24 a.

The light incident from the left side of FIG. 9 along the direction D1perpendicular to the surface of the first alignment layer 14 may includetwo polarized components. One of the components is parallel to thealignment direction of the alignment layer, and the other one of thecomponents is perpendicular to the alignment direction of the alignmentlayer. For example, the incident light may have a first component Xparallel to the first alignment direction 14 a of the first alignmentlayer 14 and a second component Y perpendicular to the first alignmentdirection 14 a. When light passes through the first dye-doped liquidcrystal layer 50, the first component X of the light is polarized by theliquid crystal molecules 50 a and therefore would stay parallel to themolecular axis 50 b′ of the dye molecules 50 b. As a result, the firstcomponent X is absorbed by the dye molecules 50 b layer by layer and theintensity of the first component X is reduced. After passing through thefirst dye liquid crystal layer 50, the light is rotated by 90±10 degreesby being polarized by the first dye-doped liquid crystal layer 50. Morespecifically, the first component X is rotated to be perpendicular tothe first alignment direction 14 a and the fourth alignment direction 38a, and the second component Y is rotated to be parallel to the firstalignment direction 14 a and the fourth alignment direction 38 a afterpassing through the first dye-doped liquid crystal layer 50.

Subsequently, the light passes through the second dye-doped liquidcrystal layer 52. The second component Y of the light is polarized bythe liquid crystal molecules 52 a and therefore would stay parallel tothe molecular axis 52 b′ of the dye molecules 52 b. As a result, thesecond component Y is absorbed by the dye molecules 52 b layer by layerand the intensity of the second component Y is reduced. After passingthrough the second dye liquid crystal layer 52, the light is rotated by90±10 degrees by being polarized by the second dye-doped liquid crystallayer 52. Specifically, the first component X is rotated to be parallelto the fourth alignment direction 38 a and perpendicular to the secondalignment direction 24 a, and the second component Y is rotated to beperpendicular to the fourth alignment direction 38 a and parallel to thesecond alignment direction 24 a after passing through the seconddye-doped liquid crystal layer 52. As shown in the right side of FIG. 9, after passing through the first dye-doped liquid crystal layer 50 andthe second dye-doped liquid crystal layer 52 as described above, theintensity of the first component X and the intensity of the secondcomponent Y of the light are both reduced. By designing the firstalignment direction 14 a perpendicular to the third alignment direction34 a being parallel, the fourth alignment direction 38 a perpendicularto the second alignment direction 24 a, the first alignment direction 14a parallel to the fourth alignment direction 38 a, and the thirdalignment direction 34 a parallel to the second alignment direction 24a, the present disclosure may effectively reduce the intensity of thelight by making the light continuously passing through the firstdye-doped liquid crystal layer 50 and the second dye-doped liquidcrystal layer 52 of the electronic device to absorb the components ofdifferent directions of the light. The light transmittance of theelectronic device in the low transmission state may be further reducedand the light shielding efficiency may be increased.

In summary, the electronic device provided by the present disclosure hasthe alignment directions of the opposite alignment layers of the liquidcrystal cell being perpendicular to each other. In this way, the liquidcrystal molecules may twist layer by layer between the two alignmentlayers when no electric field is applied. The liquid crystal moleculesand the dye molecules may be parallel to the surface of the alignmentlayer. In other words, the light absorption axes of the dye moleculesmay be kept parallel to the alignment direction of the alignment layer,so that the light absorption efficiency of the dye molecules may beimproved. Problems of light leakage at a large viewing angle may also bereduced. Furthermore, by forming two stacked liquid crystal cells toabsorb specific polarized lights by sharing the third substrate, theoverall thickness of the electronic device may be reduced.

Those skilled in the art will readily observe that numerousmodifications and alterations of the device and method may be made whileretaining the teachings of the disclosure. Accordingly, the abovedisclosure should be construed as limited only by the metes and boundsof the appended claims.

What is claimed is:
 1. A method for forming an electronic device, comprising: providing a first liquid crystal cell comprising a first substrate and a third substrate; performing a pre-cutting step to form at least a pre-cutting mark on the third substrate; forming a second liquid crystal cell by disposing a second substrate with a second conductive layer to the third substrate; and performing a cutting step to cut off portions of the first substrate and the second substrate and concurrently removing a portion of the third substrate along the pre-cutting mark.
 2. The method according to claim 1, wherein the first liquid crystal cell further comprises: a first sealant sealing a first space between the first substrate and the third substrate; and a first dummy sealant between the first substrate and the third substrate and outside the space; and the method further comprises: forming the pre-cutting mark between the first sealant and the first dummy sealant.
 3. The method according to claim 1, further comprising: forming a second sealant on the third substrate; and disposing the second substrate to the third substrate by the second sealant to seal a second space of the second liquid crystal cell between the second substrate and the third substrate, wherein the pre-cutting mark is outside the second space.
 4. The method according to claim 3, further comprising: forming a second dummy sealant on the third substrate and at a side of the pre-cutting mark opposite to the second sealant; and disposing the second substrate to the third substrate by the second sealant and the second dummy sealant.
 5. The method according to claim 1, wherein the first liquid crystal cell comprises a first conductive layer disposed on the first substrate and the second liquid crystal cell comprises a second conductive layer disposed on the second substrate, the method further comprising: forming a first conductive adhesive covering a part of a sidewall of the third substrate and directly contacting the first conductive layer and the second conductive layer.
 6. The method according to claim 1, wherein the first liquid crystal cell comprises a third conductive layer disposed on the third substrate, the method further comprising: forming another pre-cutting mark on the third substrate by the pre-cutting step; removing another portion of the third substrate along the another pre-cutting mark to expose a sidewall of the third substrate; and forming a second conductive adhesive covering a part of the sidewall of the third substrate and directly contacting the third conductive layer and the fourth conductive layer.
 7. The method according to claim 1, further comprising: forming a first dye-doped liquid crystal layer between the first substrate and the third substrate; and forming a second dye-doped liquid crystal layer between the third substrate and the second substrate, wherein the first dye-doped liquid crystal layer and the second dye-doped liquid crystal layer respectively comprise at least a dichroic dye.
 8. An electronic device, comprising: a first substrate; a second substrate on the first substrate; a third substrate between the first substrate and the second substrate; a first optical media layer between the first substrate and the third substrate; and a second optical media layer between the second substrate and the third substrate, wherein a sidewall of the third substrate is recessed from a sidewall of the first substrate and a sidewall of the second substrate to form a recessed portion, and another sidewall of the third substrate protrudes from another sidewall of the first substrate and another sidewall of the second substrate to form a protruding portion.
 9. The electronic device according to claim 8, further comprising: a first conductive layer disposed between the first optical media layer and the first substrate; a second conductive layer disposed between the second optical media layer and the second substrate; a third conductive layer disposed between the first optical media layer and the third substrate; and a fourth conductive layer disposed between the first optical media layer and the third substrate, wherein portions of the first conductive layer and the second conductive layer are exposed from the recessed portion, and portions of the third conductive layer and the fourth conductive layer are exposed from the protruding portion.
 10. The electronic device according to claim 9, further comprising: a first conductive adhesive disposed in the recessed portion and directly contacting the first conductive layer and the second conductive layer.
 11. The electronic device according to claim 9, further comprising: a second conductive adhesive disposed on the protruding portion and directly contacting the third conductive layer and the fourth conductive layer.
 12. The electronic device according to claim 8, wherein the first optical media layer and the second optical media layer are dye-doped liquid crystal layers respectively comprising at least a dichroic dye.
 13. An electronic device, comprising: a first substrate; a second substrate on the first substrate; a third substrate between the first substrate and the second substrate; a first optical media layer between the first substrate and the third substrate; and a second optical media layer between the second substrate and the third substrate, wherein the first substrate, the third substrate and the second substrate are displaced layer by layer along a direction parallel to a surface of the first substrate to form a stepped structure and along the direction, a sidewall of the third substrate is between a sidewall of the first substrate and a sidewall of the second substrate at a same side of the electronic device.
 14. The electronic device according to claim 13, further comprising: a first conductive layer disposed between the first optical media layer and the first substrate and exposed from a first step portion of the stepped structure; a second conductive layer disposed between the second optical media layer and the second substrate and exposed from a second step portion of the stepped structure; a third conductive layer disposed between the first optical media layer and the third substrate and exposed from a third step portion of the stepped structure; and a fourth conductive layer disposed between the first optical media layer and the third substrate and exposed from a fourth step portion of the stepped structure. 